It is desired that the attributes of personal care absorbent articles include low leakage of liquid waste from the absorbent article and a dry feel to the wearer. However, absorbent articles commonly fail before the total absorbent capacity of the absorbent article is utilized. Most absorbent articles are designed for a sitting or standing position and have a target area in the crotch region of the absorbent article for containment of liquid waste. The target area is typically centered within the absorbent article for a female wearer and phased forward within the absorbent article for a male wearer. The target area of the absorbent article may be flanked by containment flaps to further aid in containing the liquid waste within the target area and within the absorbent article. The crotch region may also form a bucket away from the wearer's body to hold the fluid until it is absorbed by the absorbent article. When a wearer of an absorbent article is in a side lying position, however, the absorbent article often leaks liquid waste at the leg openings, front waist region or back waist region of the absorbent article. Leakage can occur due to a variety of reasons such as saturation of the absorbent core in the target area, an inability of the target area to handle a gush of fluid, and an insufficient rate of fluid uptake by the absorbent core, especially on the second or third liquid surges.
It has been found that urination can occur at rates as high as 15 to 20 milliliters per second and at velocities as high as 280 centimeters per second. Conventional diaper absorbent structures, such as those comprising admixtures of absorbent gelling particles and cellulosic fluffed pulp, may initially uptake fluid at rates of only about 8 milliliters per second or less, depending on the web density and concentration of gelling particles. The initial uptake rates, however, for conventional absorbent articles can deteriorate once they have already received liquid surges into their absorbent cores. The disparity between liquid delivery and uptake rates can result in excessive pooling on the surface of the absorbent core before it is taken up by the absorbent core. When the wearer of the absorbent article is in a side lying position, the excess fluid follows gravity down to the containment flaps of the absorbent article. The containment flaps may be lying down on the bodyside liner of the absorbent article resulting in gaps between the body of the wearer and the containment flaps. The containment flaps lying on the bodyside liner also decreases the area in which the excess fluid can pool when the wearer is in a side lying position. The excess fluid, therefore, leaks from the absorbent article through a gap between the containment flaps and the body of the wearer or through a gap between the waist regions and the body of the wearer.
Children who wet the bed at night (“nocturnal enuresis”) tend to have higher leakage rates. The absorbency challenges are significant for night time child absorbent articles as 70% of children lay on their side and when they experience nocturnal enuresis, they generally are releasing a large volume of urine at high velocity within a single insult.
Thus, there is a need for an absorbent article with side lying leakage improvement that is able to create a space where excess fluid can pool, quickly absorb a large amount of liquid waste in the target area and reduce leakage of liquid waste from the absorbent article when the wearer of the absorbent article is in a side lying position.